Revert "persistent-mysql-2.6.2 haddock failure (yesodweb/persistent#724)"
Revert "persistent-mysql-2.6.2 haddock failure (yesodweb/persistent#724)"

This reverts commit 2817f5cde6d463a8466a644715f7ee4b7ed317b1.

creichert/stackage,soenkehahn/stackage,ethercrow/stackage,Shimuuar/stackage,mgajda/stackage,Daniel-Diaz/stackage,michalkonecny/stackage,int-index/stackage,phaazon/stackage,asr/stackage,wereHamster/stackage,massysett/stackage,garetxe/stackage,lwm/stackage,simonmichael/stackage,spencerjanssen/stackage,mrkkrp/stackage,mstksg/stackage,jonschoning/stackage,iand675/stackage,athanclark/stackage,stackbuilders/stackage,fimad/stackage,k0ral/stackage,peti/stackage,fpco/stackage,clinty/stackage